1. Field of the Invention
The present invention relates to the field of fluid machinery, and in particular to a rotation device, and a rotor compressor and a fluid motor having the same.
2. Description of the Related Art
At present, commercially available displacement compressors used most widely are mainly divided into four types: reciprocating piston compressors, screw compressors, scroll compressors and rotor compressors. For a rotor compressor, when a main shaft is rotating, an eccentric rotor revolves in close contact with an inner wall of a cylinder so as to change a crescent volume space periodically, thereby accomplishing a suction process, a compression process, and an exhaust process. Since the compression process of the rotor compressor is smooth and balanced, the rotor compressors have been applied widely to household refrigeration apparatuses such as air conditioners and refrigerators.
FIG. 1 is a schematic structural view of a prior art rotor compressor. The rotor compressor is disclosed in reference document 2 (Chinese patent application No. 200780027498.9). Referring to FIG. 1, the rotor compressor comprises a cylinder block 1, a rolling rotor 2, an eccentric sleeve 3, a driving shaft 4 with an eccentric shaft portion, a swing stop, and a helical spring. The eccentric sleeve 3 is disposed between the eccentric shaft portion of the driving shaft 4 and the rolling rotor 2 to be rotatable nimbly between them, thereby enabling an eccentric distance of the rolling rotor 2 to be adjusted and achieving a flexible rolling contact seal in operation. The eccentric sleeve 3 rotates on its eccentric center while revolving around the driving shaft. A rotating portion of the swing stop achieves a swing type separation with a swinging portion being tightly pressed against an outer circumferential surface of the rolling rotor 2 under the action of a spring force from the helical spring.
However, when the rotor compressor shown in FIG. 1 operates in a high-intensity working condition, and especially when a frequency of rotation is very high, energy loss caused by sliding frictions between sliding surfaces of the driving shaft 4 with the eccentric shaft portion and of the rolling rotor 2 and the eccentric sleeve 3 are relatively large and thus these sliding surfaces need to be lubricated with oil. After the lubricating oil entering a cylinder and the compression medium are mixed and discharged, the mixed lubricating oil and compression medium need to be separated again. In addition, since sealing is performed by the lubricating oil in a movement clearance, it is necessary to form a high pressure inside a housing of a system in order to separate the lubricating oil from discharged gas. Since an electric motor for driving rotation of the rotor compressor is mounted within the housing, a high-temperature high-pressure environment formed within the housing goes badly against insulation and heat dissipation of the drive electric motor and thus the electric motor will be easily overheated. The rotor compressor is particular compact in size due to structure of the eccentric rotor, and as described above, it has become a custom to use lubricating oil for reasons such as filling, with oil, a clearance in a position where the cylinder block and a seal sleeve come into contact with each other. This limits application of the rotor compressor to large-scale air compressors and air compressors used at a low temperature.
In the rotor compressor shown in FIG. 1, the helical spring urges an end of the swing stop so that the other end of the swing stop is pressed against the rolling rotor 2. Since the helical spring operates in a high-intensity working condition for a long time, it will very easily fault to be broken, thereby affecting a service life of the entire rotor compressor. Therefore, it is necessary to hunt for a more excellent and more reliable resetting and biasing mechanism for the swing stop. Furthermore, due to presence of a lever effect, a force between the swing stop and the rolling rotor 2 cannot be easily controlled. If the force is too large, not only wear of the swing stop is increased, but a power of the compressor is also consumed; while if the force is too small, sealing of the cylinder cannot be ensured.
In addition, a large pressure is endured by a contact portion of a head of the swing stop and a contact portion of an outer cylindrical surface of the rolling rotor 2, and a high-speed relatively sliding movement occurs between the contact portion of the head of the swing stop and the contact portion of the outer cylindrical surface of the rolling rotor 2. Therefore, there should be a sealing structure of low-friction, wear-resistant, high-efficiency, long-life time. If there is no corresponding measure, the contact portions will be very easily damaged. However, a measure in the prior art is to connect the contact portion of the head of the swing stop and the contact portion of the outer cylindrical surface of the rolling seal sleeve 2 together so that the head of the swing stop is fixed with a position of the outer cylindrical surface of the rolling seal sleeve. Although wear and seal problems of the contact portions can be solved in this way, it is impossible to achieve rolling between the outer cylindrical surface of the rolling seal sleeve 2 and a cylindrical inner wall of the cylinder block 1, thereby resulting in frictional wear and occurrence of clearance issues. Although the clearance in the portion where the cylinder block and the seal sleeve come into contact with each other can be filled with oil, this will bring about a problem of separating the compression medium from the lubricating oil.